作业帮已知x(x-1)-(x²-y)=2,求代数式[（3x²+3y²）\2]-3xy
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![已知x(x-1)-(x²-y)=2,求代数式[（3x²+3y²）\2]-3xy](/uploads/image/z/385519-31-9.jpg?t=%E5%B7%B2%E7%9F%A5x%28x-1%29-%28x%26%23178%3B-y%29%3D2%2C%E6%B1%82%E4%BB%A3%E6%95%B0%E5%BC%8F%5B%EF%BC%883x%26%23178%3B%2B3y%26%23178%3B%EF%BC%89%5C2%5D-3xy)
已知x(x-1)-(x²-y)=2,求代数式[（3x²+3y²）\2]-3xy
已知x(x-1)-(x²-y)=2,求代数式[（3x²+3y²）\2]-3xy
已知x(x-1)-(x²-y)=2,求代数式[（3x²+3y²）\2]-3xy
x(x-1)-(x²-y)=2,
x²-x-x²+y=2
x-y=-2
x²+y²-2xy=4
x²+y²=2xy+4
[（3x²+3y²）\2]-3xy
=3(2xy+4)/2-3xy
=3xy+6-3xy
=6
x(x-1)-(x²-y)=2
x²-x-x²+y=2
x-y=-2
[（3x²+3y²）\2]-3xy
=(3x²-6xy+3y²)/2
=3(x-y)²/2
=6